Hi, Can you please elaborate on how you selected your ecutwfc?
regards, On Mon, Aug 23, 2010 at 10:48 AM, jia chen <jiachen at princeton.edu> wrote: > I did similar thing before, total energy doesn't need to converge... > > On Mon, Aug 23, 2010 at 2:22 AM, Guda Karthik <karthik.guda at gmail.com> > wrote: > > Hi, > > > > The total energy doesn't converge till 80 Ryd of ecutwfc. I am using > Ni > > and Ti USPPs (Ti.pbe-sp-van_ak.UPF, Ni.pbe-nd-rrkjus.UPF). My > calculations > > become very slow while using such a large kinetic energy cutoff. am I > doing > > something wrong here? > > > > regards, > > Karthik > > > > On Tue, Aug 17, 2010 at 4:46 PM, Stefano de Gironcoli <degironc at sissa.it > > > > wrote: > >> > >> please note that the two outputs that you submitted ARE NOT examples of > >> vc-relaxation but of structural relaxation of the internal coordinates > >> only. Your question is anyway legittimate... > >> Are you sure to have converged the total energy of your system with > >> respect to cutoff to a sufficient level ? > >> when comparing different volumes one is using different basis sets in > >> the two cases. If convergence w.r.t. cutoff is not sufficient this can > >> lead to sudden decreases of the energy when increasing the volume. > >> > >> stefano > >> SISSA and DEMOCRITOS > >> > >> Guda Karthik wrote: > >> > Hi, > >> > > >> > Here are the input and output files. > >> > > >> > b19_Acklatpos_new.* - original structure > >> > > >> > b19_pwscf.* - scf calculation with a structure obtained after > >> > vc-relax > >> > > >> > Please have a look if they are of help. > >> > > >> > regards, > >> > Karthik > >> > > >> > On Sat, Aug 14, 2010 at 6:27 AM, Paolo Giannozzi > >> > <giannozz at democritos.it>wrote: > >> > > >> > > >> >> On Aug 4, 2010, at 4:41 , Guda Karthik wrote: > >> >> > >> >> > >> >>> I am trying to relax an orthorhombic structure using vc-relax > >> >>> (celldofree - xyz). I start with a structure which is at a Pressure > >> >>> of -20.5 Kbar and at the end of the vc-relax I get a structure > >> >>> which is at a pressure of -0.21 Kbar. Surprisingly, the structure > >> >>> at pressure closer to zero is higher in energy than the original > >> >>> structure by 8 * 10^-4 eV/formula unit. All the symmetry elements > >> >>> have been conserved during relaxation and the initial and final > >> >>> structures are the same. I am not able to make sense of this > >> >>> result. I observe this inconsistency in my B2 structure as well. > >> >>> Please help regarding this. > >> >>> > >> >> hard to help without input and output > >> >> > >> >> P. > >> >> --- > >> >> Paolo Giannozzi, Dept of Physics, University of Udine > >> >> via delle Scienze 208, 33100 Udine, Italy > >> >> Phone +39-0432-558216, fax +39-0432-558222 > >> >> > >> >> > >> >> > >> >> _______________________________________________ > >> >> Pw_forum mailing list > >> >> Pw_forum at pwscf.org > >> >> http://www.democritos.it/mailman/listinfo/pw_forum > >> >> > >> >> > >> > > >> > > >> > > >> > > >> > > ------------------------------------------------------------------------ > >> > > >> > _______________________________________________ > >> > Pw_forum mailing list > >> > Pw_forum at pwscf.org > >> > http://www.democritos.it/mailman/listinfo/pw_forum > >> > >> _______________________________________________ > >> Pw_forum mailing list > >> Pw_forum at pwscf.org > >> http://www.democritos.it/mailman/listinfo/pw_forum > > > > > > > > -- > > Karthik Guda > > Graduate Student > > Materials Engineering > > Purdue University > > > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > > > > -- > Jia Chen > > Dept of Chemistry > Princeton University > Princeton, NJ 08544 > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Karthik Guda Graduate Student Materials Engineering Purdue University -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100824/7afbeb4a/attachment.htm
